Record Details
Evaluating "nuisance" beaver relocation as a tool to increase coho salmon habitat in the Alsea Basin of the central Oregon Coast Range
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Evaluating "nuisance" beaver relocation as a tool to increase coho salmon habitat in the Alsea Basin of the central Oregon Coast Range |
| Names |
Petro, Vanessa M.
(creator) Taylor, Jimmy D. (advisor) Sanchez, Dana M. (advisor) |
| Date Issued | 2013-08-14 (iso8601) |
| Note | Graduation date: 2014 |
| Abstract | Many stakeholders involved with stream restoration in the Pacific Northwest have discussed the potential benefits of using beaver dam construction activities (Castor canadensis) as a management tool to improve degraded stream habitat for anadromous salmon species. In addition, there has been growing interest in using nuisance beavers, primarily controlled by lethal methods, to alleviate human-wildlife conflict issues and subsequently improve Coho salmon (Oncorhynchus kisutch) rearing habitat. To understand the efficacy of using beavers as a stream restoration tool, I studied the movement, survival, and dam construction of nuisance beavers relocated to the Alsea Basin of the Oregon Coast Range. I trapped and transported 38 individuals to the nine release sites where dams constructed by beavers would benefit coho salmon productivity. All adult and sub-adult beavers were equipped with tail-mount transmitters. Beavers moved an average of 3.3 ± 0.2 (SE) stream km from release sites. The maximum distance moved from a release site was 29.2 stream km. Post-release movements did not differ significantly by age or sex. All radio-tagged individuals dispersed from their release sites. Survival 16 weeks post-release was 47%. Twelve of the radio-tagged beavers died within 90 days of release. Three cause-specific sources of mortality were identified including predation, natural causes, and human related. Mountain lions (Puma concolor) were responsible for the majority of predation based mortalities. Of the 38 nuisance beavers relocated, only five individuals contributed to the nine dams constructed post-release. Six of these dams were built by one male: female pair. All dams constructed by relocated beavers were ephemeral. In addition to monitoring post-release beaver responses, I also assessed the utility of pre-existing models to identify release site locations. Thus, I explored dam habitat relationships of extant and relocated colonies throughout the Alsea Basin. I determined the utility of locally developed spatial models was reasonable. Analysis revealed primary pool habitat and valley floor width variables as strong indicators of beaver dam sites. I conclude beaver relocation as a tool for stream restoration in the Alsea Basin may not offer an effective solution to lethal control measures and coho habitat enhancement due to low survival rates, unwanted movement and establishment outside of suitable release sites, and lack of dam construction. |
| Genre | Thesis/Dissertation |
| Access Condition | http://creativecommons.org/licenses/by-nd/3.0/us/ |
| Topic | dam |
| Identifier | http://hdl.handle.net/1957/42875 |
